1. Field of the Invention
The present invention relates to soldering irons of the type having a replaceable tip heater cartridge in which the soldering tip is formed as part of the heater cartridge and can be connected to the soldering tool handpiece and removed therefrom by a simple plug-in and pull-out operation.
2. Description of Related Art
Soldering irons which use a replaceable tip heater cartridge in which the soldering tip is formed as part of the heater cartridge and where the cartridge can be connected to the soldering tool handpiece and removed therefrom by a simple plug-in and pull-out operation are known, one example being that of U.S. Pat. No. 4,839,501. Such known soldering irons possess several shortcomings. Firstly, loads applied to the soldering tip are transferred to the electrical connectors of the handpiece so that they can become damaged with extended use, and these connectors are not easily replaced. Furthermore, the coaxial connectors used for electrical and mechanical connection of the cartridge to the handpiece prevent use of cartridges with other than rotational symmetric, i.e., conical, soldering tips due to the fact that no means exists to provide accurate tip-to-handle orientation or to maintain whatever tip orientation is initially set, particularly if the handle is one half of a tweezer arrangement in which maintenance of the tip orientation is critical to its function.
In view of the foregoing, it is an object of the present invention to provide a replaceable tip heater cartridge, of the type in which the soldering tip is formed as part of the heater cartridge and the cartridge can be connected to the soldering tool handpiece and removed therefrom by a simple plug-in and pull-out operation, which is constructed in a manner that loads applied to the soldering tip will not be transferred to the electrical connectors of the handpiece so that they will not become damaged even with extended use or abusive use.
It is another object of the present invention to provide a replaceable tip heater cartridge, of the type in which the soldering tip is formed as part of the heater cartridge and the cartridge can be connected to the soldering tool handpiece and removed therefrom by a simple plug-in and pull-out operation, which is constructed in a manner that an accurate tip-to-handpiece orientation is easily obtained and maintained by the provision of a rigid mechanical interlock between the tip heater cartridge and the handpiece which ensures that there is no rotational or lateral movement between them.
Yet another object of the present invention is to provide a handpiece with an electrical connector assembly that can easily be removed for replacement or maintenance.
Because fumes are produced during the soldering process that are harmful to the electrical connections, it is an additional object to prevent such fumes from flowing into the connector assembly.
These and other objects and advantages are achieved in accordance with the present invention which, in accordance with a preferred embodiment, has a precision molded plastic sleeve on the cartridge body. The sleeve is provided with an axially extending, radially projecting key which assures accurate tip-to-handpiece orientation and also produces a rigid mechanical interlock between the tip heater cartridge and the handpiece to ensure that there is no axial, rotational or lateral movement or load transmitted from the tip of the tip heater cartridge to the electrical connector. In a particularly preferred arrangement, the end of the key acts with the handle keyway to prevent over insertion of the tip heater cartridge into the handpiece, which could damage the electrical connector assembly, and an O-ring on the electrical connector assembly acts to produces a seal relative to the body of the cartridge that prevents solder fumes from flowing into the connector assembly. The O-ring also serves to assist in retaining the cartridge within the handle and provides additional lateral support to the cartridge.
These and other features of the invention are described in further detail below with reference to the accompanying drawings.